JPH11230747A - Laser irradiation device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To increase the received light quantity of a reflected laser beam and to enlarge the using range of a laser irradiation device without enlarging an optical system and a driving system. SOLUTION: This device is provided with a laser beam emitting part 5 for emitting a laser beam 20, a turning part 6 for rotationally irradiating the laser beam from the laser beam emitting part 5 and forming a laser plane, an inclination setting part for inclining the turning part 6, a target 2 for reflecting the laser beam from the turning part 6, and a light receiving part 32 for receiving the reflected laser beam in a prescribed direction parallel to the laser plane. The reflected laser beam reflected at the target 2 is received without interposing the turning part 6, and the target 2 is detected by the light receiving part 32.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a laser irradiation apparatus for irradiating a laser beam with a laser beam and forming a reference plane by the laser beam.

[0002]

2. Description of the Related Art A laser irradiation apparatus irradiates a laser beam onto a reference plane and forms a reference plane by the laser beam. The reference line is on the reference plane. Therefore, when the reference plane is a horizontal plane, the reference line is horizontal, and the height of the reference line is the height of the reference plane, and the reference line is used as a reference for horizontal or height.

A laser beam emitted from a laser irradiator uses visible light or invisible light. When visible light is used, the maximum output of the laser beam is limited in order to ensure safety for workers and others. ing. For this reason, in a laser irradiation apparatus using visible light, in order to obtain higher visibility, a predetermined point is irradiated statically, or a reciprocating scan is performed in a predetermined range around the predetermined point to increase the apparent brightness. The visibility is improved. In some cases, the laser irradiation device includes a target for determining the predetermined point, and the laser irradiation device includes the target and a rotary irradiation device main body that irradiates a laser beam. The rotary irradiation device main body of such a laser irradiation device has a function of detecting a target, and the rotary irradiation device main body is provided with a light receiving unit that detects reflected light from the target. The light receiving unit detects reflected light from the target, and the position of the target is detected based on the detection result of the light receiving unit.

A conventional rotary irradiation apparatus main body 1 and a target 2 will be described with reference to FIGS.

The main body of the rotary irradiation device 1 includes a light emitting section 5, a rotating section 6, a light receiving section 7, a control section (CPU) 8, a light emitting element driving section 9, and a scanning motor driving section 10.

The light emitting section 5 will be described.

On the optical axis of a laser diode 11 for emitting a laser beam 20, a collimator lens 12 and a perforated mirror 13 are sequentially arranged from the laser diode 11 side.
Laser beam 2 emitted from the laser diode 11
Numeral 0 is converted into parallel light by the collimator lens 12, and is emitted to the rotating unit 6 through the perforated mirror (or half mirror) 13.

The rotating portion 6 is for turning the optical axis of the laser beam 20 incident from the light emitting portion 5 by 90 °, emitting the laser beam 20 in the horizontal direction, and further rotating. The optical axis 20 is turned 90 ° by the pentaprism 14. The pentaprism 14 is provided on a rotating support 15 that rotates about the optical axis of the light emitting section 5, and the rotating support 15 is connected to a scanning motor 18 via a scanning gear 16 and a driving gear 17. The rotation state of the rotation support 15 is detected by an encoder 19 provided on the rotation support 15, and a detection signal of the encoder 19 is input to the control unit (CPU) 8.

A reflected laser beam 20 ′ from the target 2 is incident on the rotating portion 6, and the reflected laser beam 20 ′ incident on the pentaprism 14 is directed toward the perforated mirror 13. Deflected, the perforated mirror 13 reflects the reflected laser beam 20 ′ toward the light receiving section 7.

Next, the light receiving section 7 will be described.

A condenser lens 21 and a light receiving element 22 are arranged on the reflection optical axis of the perforated mirror 13 by the perforated mirror 1.
The light receiving state is output from the light receiving element 22 to a reflected light detecting unit 23 described later.

In the reflected light detecting section 23, the reflected laser beam 2
The light receiving state of 0 ', that is, the reflection state of the laser beam 20 at the target 2 is detected, and the detected state is output to the control unit 8. The control unit 8 will be described.

The controller 8 receives signals from the encoder 19 and the reflected light detector 23.

The control section 8 drives the light emitting element driving section 9 to emit the laser beam 20 and controls the scanning motor driving section 10 based on a signal from the reflected light detecting section 23. The scanning motor driving unit 10 drives the scanning motor 18 based on a control signal from the control unit 8, and drives the driving gear 17, the scanning gear 16, and the rotation support 15.
The pentaprism 14 is rotated through. The rotation state and rotation position of the pentaprism 14 are determined by the encoder 1
The signal from the control unit 9 is fed back to the control unit 8 so that the control unit 8 detects the signal. By rotating the pentaprism 14 with the laser beam 20 emitted from the laser diode 11, the laser beam 20 irradiated in the horizontal direction is rotated, and a reference plane is formed by the laser beam 20.

The target 2 has a reflecting surface that makes it possible to recognize the target 2 when the laser beam 20 scans the target 2 or to detect the center of the target 2. Hereinafter, the target 2
14A and 14B will be described.

The reflection layer 26 and the reflection layer 2 are provided on both ends of the substrate 25.
7 is formed, and a non-reflection surface exists in the middle part between the reflection layer 26 and the reflection layer 27. The reflection layer 26 and the reflection layer 27 reflect the laser beam 20 emitted from the rotation unit 6 so as to be incident on the rotation unit 6 again. Since there are two reflecting layers, when the laser beam 20 scans the target 2 as shown in FIG. 14 (A), the reflected laser beam 20 'from the target 2 becomes an intermediate portion as shown in FIG. 14 (B). Are in the form of two pulses. Therefore, the target 2 can be identified based on the light reception result.

When the target 2 is detected, the rotary irradiation device main body 1 reciprocally scans the laser beam 20 within a required range around the target 2.

[0018]

Recently, the range of use of a laser irradiation apparatus has been expanded, and it has become necessary to capture a target located farther away. However, as described above, the maximum output of the laser beam is limited. Therefore, in order to make it possible to recognize a distant target, the amount of received light should be increased without loss. As one of means for increasing the amount of received light, the size of the perforated mirror 13 of the light receiving system may be increased. However, there is a problem in that the optical system including the pentaprism 14 becomes larger and the driving system related to the optical system becomes larger.

The present invention has been made in view of the above circumstances, and aims to increase the amount of reflected laser beams received without increasing the size of an optical system and a drive system, thereby expanding the range of use of a laser irradiation apparatus.

[0020]

According to the present invention, there is provided a laser emitting section for emitting a laser beam, a rotating section for irradiating a laser beam from the laser emitting section to form a laser plane, and tilting the rotating section. The present invention relates to a laser irradiation device including a tilt setting unit, a target that reflects a laser beam from the rotating unit, and a light receiving unit that receives a reflected laser beam in a predetermined direction parallel to the laser plane. The present invention relates to a laser irradiation apparatus provided with a mask for limiting a light receiving range on a light receiving optical path of a light beam, wherein the laser emitting section emits a polarized laser, and the target preserves and reflects the polarization direction and a polarization direction. And a polarization converting / reflecting portion for converting and reflecting the light, and the light receiving portion receives a reflected laser beam whose polarization direction has been converted and a first light receiving means for receiving the reflected laser beam whose polarization direction has been preserved. The present invention relates to a laser irradiating device having a second light receiving means and a laser irradiating device having at least a tilt setting unit and a rotating unit for rotating the light receiving unit. The present invention relates to a laser irradiation apparatus having control means for controlling rotation of a rotating unit so that a tilt direction matches a tilt direction of the target, and a setting direction of the tilt setting unit and the target based on light reception of the light receiving unit. The present invention relates to a laser irradiation apparatus having a display means for displaying a coincidence when the directions coincide with each other, and further controls an inclination setting section such that a laser beam is directed to the center of the target based on light reception of the light receiving section. The present invention relates to a laser irradiation apparatus having control means, and receives a reflected laser beam reflected by the target without passing through the rotating part, and targets the target by the light receiving part. Out to.

[0021]

Embodiments of the present invention will be described below with reference to the drawings.

1 to 3, the same components as those shown in FIGS. 13 and 14 are denoted by the same reference numerals.

The laser irradiation device includes a rotary irradiation device main body 1, a target 2, and a rotating section 3 for rotating the rotary irradiation device main body 1 about a vertical axis. It is installed on a tripod or the like (not shown) via 3. Further, the rotary irradiation device main body 1 has a light emitting portion 5 for emitting a laser beam 20, a rotating portion 6 for rotatingly irradiating the laser beam onto a reference plane, a leveling of the rotary irradiation device main body 1, and an inclination for setting the inclination of the reference plane. It mainly comprises a setting unit 30, an inclination detecting unit 31, and a light receiving unit 32.

A collimator 33 is provided on the upper surface of the rotary irradiation device main body 1, and the direction of the rotary irradiation device main body 1 with respect to the target 2 is roughly set by the collimator 33. Further, the rotary irradiation device main body 1 has a light receiving window 34 below the rotating portion 6, and the reflected laser beam 20 ′ reflected from the target 2 enters through the light receiving window 34, The light is received by the light receiving section 32 provided inside the main body 1.

The rotating section 3 is provided below the rotating irradiation apparatus main body 1 and is attached to a tripod (not shown) via a leveling screw 4.

A rotary seat 80 is provided on the lower surface of the rotary irradiation device main body 1.
The rotating seat 80 is attached to the rotating base 81 by the bearing 8.
2, a rotatable portion driven gear 83 is fixed to the rotary seat 80. The rotation base 8
1 is provided with a rotating section motor 84,
The rotation unit driving gear 85 fitted to the output shaft of No. 4 meshes with the rotation unit driven gear 83. A rotary encoder 86 is provided between the rotary seat 80 and the rotary base 81. In the figure, reference numeral 87 denotes a contact for supplying power from the rotating irradiation device main body 1 to the rotating unit 3.

The light emitting portion 5 is supported by a spherical portion 35 and a seat 36 (or gimbal) so as to be freely tiltable.
A rotating part 6 is rotatably provided at the upper end of the light emitting part 5,
A scanning gear 16 is fitted to the rotating portion 6, and the scanning gear 1 is
Reference numeral 6 meshes with a drive gear 17 of a scanning motor 18 fixed to the light emitting section 5. By the driving of the driving gear 17, the rotating portion 6 is rotated. 2 horizontally from the light emitting section 5
The two tilting arms 37 (one not shown) extend, and the two tilting arms are orthogonal to each other.
0 (one not shown).

The tilt setting section 30 will be described.

The tilting motor 39 mounted on the casing 38 of the rotary irradiation device main body 1 is connected to an inclination setting screw 42 via a gear train 41, and the inclination setting screw 4
A slide nut 43 is screwed into 2, and the slide nut 43 is engaged with the tip of the tilt arm 37. Thus, the inclination of the light emitting unit 5 in any direction can be set by the two sets of inclination setting units 30.

The inclination angle of the light emitting section 5 is
Is detected by the inclination detection unit 31 provided at the lower end of the sensor. The inclination detecting section 31 includes two orthogonal inclination sensors 4.
4, 45 and an inclination calculating section (not shown) for detecting the inclination of the light emitting section 5 based on the output signals from the inclination sensors 44, 45. The drive of the tilt motor 39 is controlled based on the output from the tilt detector 31. The tilt setting is achieved by driving the tilt motor 39 at an angle converted into the number of pulses.

The light receiving section 32 may be fixed to the casing 38, but is preferably provided on the light emitting section 5 so that the light receiving section 32 can be tilted integrally with the light emitting section 5. The light receiving section 32 will be described.

The condenser lens 48 faces the light receiving window 34.
And a reflecting mirror 49 is arranged on the optical axis of the condenser lens 48. The optical axis of the condenser lens 48 is parallel to a reference plane formed by the rotation of the laser beam 20. A light receiving element 50 is provided below the reflecting mirror 49, and the reflected laser beam 20 'is focused on the light receiving element 50. The light receiving element 50 is a line sensor having a length in a scanning direction of the laser beam 20 (a direction perpendicular to the plane of FIG. 3), and a mask 51 is provided on a front surface of the light receiving element 50. The mask 51 blocks noise light from entering the light receiving element 50. As shown in FIG. 4, a long slit 52 is formed in the scanning direction of the reflected laser beam 20 '. The reflecting mirror 49 may be omitted and the light receiving element 50 may directly receive light.

The light receiving signal from the light receiving element 50 is input to the reflected light detecting unit 23, and the state of the laser light reflection on the target 2 detected by the reflected light detecting unit 23 is input to the control unit 8. A signal from the rotary encoder 86 is input to the control unit 8. The control unit 8 drives the laser diode 11 via the light emitting element driving unit 9,
The scanning motor 18 is driven via the scanning motor driving unit 10, and the rotating motor 84 is driven via the rotating motor driving unit 88.
Drive.

The control section 8 receives a signal from the light receiving section 32,
Alternatively, based on signals from the tilt sensors 44 and 45, the encoder 19, and the rotary encoder 86, the direction of the rotary irradiation device main body 1 is displayed on a display unit (not shown) of the rotary irradiation device main body 1.
Information about the reference plane formed by the laser beam 20 is displayed. For example, a display of coincidence in a state where the rotary irradiation device main body 1 faces the target 2, or in what direction and how much the rotary irradiation device main body 1 is rotated with respect to the target 2, The inclination angle, the inclination direction, and the like are displayed.

The target 2 used in the present embodiment is the same as that described above, and the description is omitted.

The operation will be described below.

The target 2 is set at a predetermined reference position, leveling is roughly performed by the leveling screw 4, and the rotary irradiation device main body 1 is leveled by the tilt setting unit 30 and the tilt detecting unit 31. The rotation irradiation device main body 1 is driven.

The laser diode 11 is driven via the light emitting element driving section 9, and a laser beam 20 is emitted from the laser diode 11. The laser beam 20 is converted into parallel light having a required light beam diameter by the collimator lens 12, is reflected in the horizontal direction by the pentaprism 14, and is emitted on a predetermined reference plane. The pentaprism 14 is rotated by the scanning motor 18 via a driving gear 17, a scanning gear 16, and a rotating support 15. The rotation of the pentaprism 14 causes the laser beam 20
Are rotationally irradiated to form a reference plane.

The target 2 is set on a reference line,
The laser beam 20 scans across the target 2. The laser beam 20 traverses the reflection layers 26 and 27, and as shown in FIG.
The reflected laser beam 20 ′ is reflected in a pulse form by 6 and 27. As described above, since the laser beam 20 has a required beam diameter, the reflected laser beam 20 '
And enters the light receiving unit 32.

The reflected laser beam 20 ′ passes through the condenser lens 48, and is reflected by the reflecting mirror 49 on a light receiving / receiving element 50.
And is collected on the light receiving element 50. The mask 51 blocks noise light incident on the light receiving element 50, and improves the light receiving accuracy of the light receiving element 50. The light receiving section 32 is fixed, and the pentaprism 14 rotates. As described above, the light receiving element 50
0 'is a line sensor long in the scanning direction, and the slit hole 52 is also long in the scanning direction of the reflected laser beam 20'.
0 'can be detected.

The light receiving signal from the light receiving element 50 is input to the reflected light detecting section 23, and the reflected light detecting section 23 detects the position of the target 2 and the center position of the target 2 based on the signal from the light receiving element 50. . The target 2 is 2
Since the reflected laser beam 20 ′ is reflected in two pulses, the light receiving section 32 can reliably detect the target 2.
Further, the center of the target 2 is located between the two pulsed reflected laser beams 20 ′, and the light receiving section 32 can also detect the center of the target 2.

The result of detection of the target 2 by the reflected light detecting unit 23 is input to the control unit 8, and the control unit 8 drives the scanning motor based on the signal from the reflected light detecting unit 23 and the signal from the encoder 19. The scanning motor 18 is driven via the unit 10 to control the position rotation of the pentaprism 14. Thus, the laser beam 20 is controlled so as to irradiate a point on the target 2 or reciprocally scan the center of the target 2 with a required width.

As a method for detecting the target 2, a method other than rotating the rotary unit 6 and rotating and scanning the laser beam is another method for rotating the rotary unit 6 within a required angle range. The rotating irradiation unit main body 1 may be rotated by driving the rotating unit motor 84 of the rotating unit 3 while reciprocally scanning the light beam within a required angle range.

In this embodiment, the reflected laser beam 2
Since the light receiving system of 0 'is separated from the light projecting system of the laser beam 20, the beam diameter of the laser beam 20 can be selected without being limited to the shape of the pentaprism 14, etc. Can be increased, and the reach of the laser beam 20 can be increased.

Next, the setting of the inclination will be described.

When the target 2 is detected by irradiating a laser beam, the rotation angle of the rotary unit 6 at the time of detection is detected by the encoder 19, and the direction of the rotary irradiation device main body 1 is determined by the rotary encoder 86. Detected,
The controller 8 calculates a deviation between the encoder 19 and the rotary encoder 86, and detects an angular displacement of the rotary irradiation device main body 1 with respect to the target 2 based on the deviation.
The rotation unit motor drive unit 88 is driven based on the angular displacement, and the rotation unit motor drive unit 88 drives the rotation unit motor 84 so that the angular displacement does not occur. Rotate. The rotation amount is detected by the rotation unit encoder 86, and in a state where the rotary irradiation device main body 1 faces the target 2, the inclination setting unit 30 and the inclination detection unit 31 are driven to rotate the light emitting unit 5 and rotate. The part 6 is inclined at a predetermined angle.

The tilt setting by the tilt setting section 30 drives the tilt motor 39 in pulses and rotates the tilt motor 39 by the number of pulses corresponding to the set tilt angle.

After the inclination is set, the rotating unit 6 is rotated to form an inclined reference plane inclined at a predetermined angle in a predetermined direction by a laser beam. Alternatively, reciprocal scanning is performed at a required angle around the target 2.

Further, the reference plane of the laser beam can be inclined in any direction. After the rotating irradiation apparatus main body 1 is directly opposed to the target 2, the rotating unit motor 84 is driven to rotate, for example, 90 ° to form a laser beam reference plane inclined in a direction perpendicular to the target 2 direction. be able to.

The collimator 33 is used when the rotary irradiation device main body 1 is roughly set in a predetermined direction as described above, or when the rotary unit 3 does not operate normally. Furthermore,
It is used when setting the direction of the laser irradiation device that does not include the rotating unit 3.

In order to set the direction of the laser irradiating apparatus without the rotating unit 3, the rotary irradiating apparatus main body 1 is set on a rotating base such as a tripod, and after the leveling, the directions are roughly adjusted using a collimator. Next, the rotary unit 6 is rotated to irradiate a laser beam, thereby detecting the target 2. By detecting the target 2, the direction of the rotary irradiation device main body 1 and the target 2
Is calculated, and a correction direction and a correction angle are displayed on a display unit (not shown) of the rotary irradiation device main body 1. The operator rotates the rotary irradiation device main body 1 according to the display to correct the direction, and confirms that the display unit displays the coincidence.

When the setting of the direction of the rotary irradiation device main body 1, that is, the setting of the tilt direction is completed, the tilt angle is set thereafter.

Referring to FIG. 5, a specific configuration in which the light emitting section 5 and the light receiving element 50 are integrally tiltably provided will be described.

The vertical projection lens barrel 5 is mounted on the tilting block 55.
The laser diode 11 is provided at the bottom of the light projecting lens barrel 56, and the collimator lens 12 is provided on the optical axis of the laser diode 11. The upper end of the light-emitting barrel 56 is a hollow shaft 57,
The rotating support 1 is attached to the shaft 57 via a bearing 58.
5 is provided rotatably. The scanning gear 16 is formed around the upper end of the rotating support 15, and the driving gear 17 of the scanning motor 18 meshes with the scanning gear 16. The encoder 19 is provided at the lower end of the rotary support 15.

The projecting lens barrel 56 is mounted on the tilting block 55.
Hook-shaped light receiving lens barrel 5 comprising a vertical lens barrel portion 59a parallel to the vertical axis and a horizontal lens barrel portion 59b continuous with the upper end of the vertical lens barrel portion 59a.
9, the condenser lens 48 is provided at the opening end of the horizontal barrel 59b, and the light receiving element 50 is provided at the bottom of the vertical barrel 59a. The reflecting mirror 49 is provided at a corner formed by the vertical lens barrel 59a and the horizontal lens barrel 59b, and the mask 51 is provided so as to cover the light receiving surface of the light receiving element 50. As described above, the light receiving element 50 and the slit hole 52 formed in the mask 51 are elongated in the scanning direction of the reflected laser beam 20 '(the direction perpendicular to the paper surface).

Thus, the light emitting section 5 and the light receiving section 32 in FIG. 5 have an integral structure and tilt at the same time. Note that the light receiving section 32 is
If the light receiving portion 32 is provided integrally with the rotation support 15 side, the light receiving portion 32 rotates integrally with the rotating portion 6 and tilts integrally. In this case, the light receiving element 50 does not need to be a line sensor, and the slit hole 52 of the mask 51 may be a round hole.

Next, a second embodiment of the present invention will be described with reference to FIGS.

In FIG. 6, the same components as those shown in FIG. 3 are denoted by the same reference numerals, and description thereof will be omitted.

In this embodiment, the polarized laser beam 20 is used as the laser beam to be irradiated, so that the accuracy of light reception is improved and the center of the target 2 can be reliably detected.

The laser diode 11 of the light emitting section 5
Emits a linearly polarized laser beam, and a 光 λ birefringent member 60 is provided on the pentaprism side of the collimator lens 12. Therefore, the laser beam rotationally scanned from the collimator lens 12 is a circularly polarized laser beam 20. Incidentally, since the laser emitting direction and the light receiving direction are determined, the polarization direction may be adjusted to be linearly polarized light.

The collimator lens 12 of the light emitting section 5
A １ ／ λ birefringent member 60 is provided on the side of the pentaprism 14 on the optical axis, and a λλ birefringent member 61 is provided on the light-receiving section 32 on the reflection side of the reflecting mirror 49. A polarizing beam splitter 62 is provided between the λλ birefringent member 61 and the light receiving element 50. The polarizing beam splitter 62 transmits a reflected laser beam 20 ′ having a polarization plane in the same direction as the polarized laser beam 20, and reflects a reflected laser beam 20 ′ having a 90 ° polarization plane different from that of the polarized laser beam 20. The reflected laser beam 20 ′ transmitted through the polarization beam splitter 62 is focused on the light receiving element 50, and the reflected laser beam 20 ′ reflected on the polarization beam splitter 62 is focused on the light receiving element 63.

The light receiving element 63, like the light receiving element 50, is a line sensor that is long in the scanning direction of the reflected laser beam 20 '(perpendicular to the plane of FIG. 6). 65 are provided. The mask 65
Is for blocking the incidence of noise light on the light receiving element 63. As shown in FIG. 7, a slit hole 66 long in the scanning direction of the reflected laser beam 20 '(perpendicular to the plane of FIG. 6) is formed. Has been established.

The light receiving signals from the light receiving elements 50 and 63 are input to the reflected light detecting section 23.

FIGS. 8, 9A and 9B show a target 2 used in the second embodiment.

Another example of the target 2 will be described with reference to FIGS. 8, 9A and 9B. The target 2
Then, the strip-shaped reflective layers 68a and 68b are
7 is provided on the left and right sides, so that the central portion of the substrate 67 is exposed in a strip shape. Further, λ / 4 birefringent members 69a and 69b are provided on the respective reflection layers 68a and 68b so as to overlap with the right half. The portions where the reflection layers 68a and 68b are exposed are the polarization preserving and reflecting portions 70 that preserve and reflect the polarization direction of the laser beam, and the λ / 4 birefringent members 69a and 69b.
The portion where is attached is a polarization conversion reflection portion 71 that converts the polarization direction and reflects the light. Thus, the combined reflection part composed of the combination of the polarization preserving reflection part 70 and the polarization conversion reflection part 71 is
Provide a set. The substrate 67 may be provided with the reflective layers 68a and 68b so that not only the central part but also the peripheral part is exposed. Further, three or more sets of combination reflection units may be provided.

When the circularly polarized laser beam 20 is scanned as shown in FIG. 9A, when the laser beam 20 passes through the reflective layer 68a, the polarization plane is preserved and the laser beam 20 is reflected, and the λ / 4 birefringent member 69a is reflected. When passing through, a circularly polarized laser beam having a polarization plane different from λ / 4 is reflected, and when passing through a portion where the substrate 67 is exposed, the laser beam 20 is not reflected. When passing through the reflection layer 68b, the polarization plane is preserved. When the laser beam 20 is reflected and passes through the λ / 4 birefringent member 69b, a circularly polarized laser beam having a polarization plane different from λ / 4 is reflected.

For example, the reflected laser beam 20 ′ reflected by the reflection layer 68 a enters the light receiving portion 32 and passes through the light receiving ４λ birefringent member 61, thereby being the same as the reflected laser beam 20 ′. It is changed to linearly polarized light having a plane of polarization in the direction. The light passes through the polarizing beam splitter 62 and enters the light receiving element 50. Further, since the light is not reflected by the polarization beam splitter 62, it does not enter the light receiving element 63. Therefore, only the light receiving element 50 outputs a light receiving signal.

Next, the reflected laser beam 20 ′ reflected by the reflection layer 69 a enters the light receiving section 32 and passes through the light receiving λλ birefringent member 61, thereby forming the reflected laser beam 20 ′. It is changed to linearly polarized light having polarization planes in directions different by 90 °. The polarizing beam splitter 62 reflects the reflected laser beam 20 'but does not transmit it. Therefore, the light receiving element 63 receives the reflected laser beam 20 ', but the light receiving element 50 does not receive the reflected laser beam 20'.
The light receiving signal from only the light receiving element 63 is reflected light detection unit 23
Is output to Further, when the laser beam 20 passes through the exposed portion of the substrate 67, the laser beam 20 is not reflected, and neither the light receiving element 50 nor the light receiving element 63 receives the reflected laser beam 20 '.

When the difference between the light receiving signals from the light receiving element 50 and the light receiving element 63 input to the reflected light detecting section 23 when the laser beam 20 scans the target 2 is obtained, FIG. ), And two signals are obtained which are clearly divided at the non-reflection portion and whose signs are inverted. Thus, by detecting the signal at the time of the inversion, the ambiguity of the rising of the signal can be removed, and the reflected light beam from the target 2 can be accurately and reliably recognized. Time difference t
Since 1 is unique to target 2, the time difference t1
Is detected, it can be confirmed that the target 2 is accurate. Therefore, even if there is unnecessary reflected light from the laminated glass or the like, malfunction does not occur.

FIGS. 10A and 10B show another target 2. The rectangular reflective layer 68 is divided into two parts along a diagonal line, and one of the divided surfaces has a λ / 4 multiple. The bending member 69 is attached. Also in this case, the reflection layer 68
Is output from the light receiving element 50 according to the line segment crossed by the laser beam 20, and the signal corresponding to the line segment crossed by the laser beam 20 is output from the light receiving element 63 through the λ / 4 birefringent member 69. Is done. Thus, by obtaining the difference between the signal from the light receiving element 50 and the signal from the light receiving element 63, the signal shown in FIG. 10B is obtained. The light receiving times t2 and t3 are proportional to the above-mentioned line segments, and the position where the two intersecting line segments are equal becomes the center of the target 2. Therefore, by detecting the light receiving time t2 = t3, the target 2 is detected.
Can be detected.

When the target 2 shown in FIG. 10 is used, automatic setting of the tilt angle can be performed.

The target 2 is scanned by rotating or reciprocating scanning, and the inclination setting unit 30 is operated until the center of the target 2 is detected from the output of the light receiving unit. While scanning the target 2 by laser beam rotational scanning or reciprocating scanning, the tilt setting unit 30 is operated, and the light emitting unit 5 and the rotating unit are rotated until the center of the target 2 is detected from the output of the light receiving unit 32. Tilt 6 After detecting the center of the target, the rotary unit 6 is rotated or reciprocally rotated at a required angle to form a laser plane.

In the third embodiment shown in FIG. 11, the pentaprism 14 irradiates a linearly polarized laser beam 20. The target 2 used is shown in FIGS.
It is indicated by 0.

In FIG. 11, the same components as those shown in FIG. 3 are denoted by the same reference numerals, and description thereof will be omitted.

The light receiving element 50 and the light receiving element 63 are arranged side by side in the scanning direction of the laser beam 20 (the direction perpendicular to the paper surface). A polarizing plate 73 is provided between the reflecting mirror 49 and the light receiving element 50, and a polarizing plate 74 is provided between the reflecting mirror 49 and the light receiving element 63. The polarizing plate 74 and the polarizing plate 73 are different from each other in the polarization plane by 90 °, and the polarizing plate 73 transmits a laser beam having the same polarization plane as the laser beam 20.

The reflection layer 68, that is, the polarization preserving reflection section 70
The reflected laser beam 20 ′ is transmitted through the polarizing plate 73 and is blocked by the polarizing plate 74. The reflected laser beam 20 ′ reflected by the polarization conversion / reflection unit 71 is blocked by the polarizing plate 73 and passes through the polarizing plate 74. Therefore, the reflected laser beam 2 reflected by the polarization preserving reflection unit 70
0 'is received only by the light receiving element 50, and the reflected laser beam 20' reflected by the polarization conversion reflector 71 is received only by the light receiving element 63.

By calculating the difference between the signals from the light receiving element 50 and the light receiving element 63, the signals shown in FIGS. 9 and 10 can be obtained in the present embodiment.

[0078]

As described above, according to the present invention, since the irradiation optical system and the light receiving optical system are separated from each other, the optical system of the light receiving section is not restricted by the optical system of the projection system, and the irradiation laser beam Thus, various excellent effects can be exhibited, such as making it possible to increase the light beam diameter, increase the amount of received light, increase the projection distance of the laser beam, and form a laser beam irradiation reference plane over a wide range.

[Brief description of the drawings]

FIG. 1 is an external view showing an embodiment of the present invention.

FIG. 2 is a sectional view showing a main part of the embodiment of the present invention.

FIG. 3 is a block diagram showing an embodiment of the present invention.

FIG. 4 is a view taken in the direction of arrow A in FIG. 3;

FIG. 5 is a sectional view showing a structure of a main part of the embodiment of the present invention.

FIG. 6 is a block diagram showing a second embodiment of the present invention.

FIG. 7 is a view taken in the direction of arrows BB in FIG. 6;

FIG. 8 is a perspective view of a target used in the present embodiment.

FIGS. 9A and 9B are diagrams illustrating the operation of the target.

FIGS. 10A and 10B are explanatory diagrams of an operation of a target used in the present embodiment.

FIG. 11 is a main part book diagram showing a third embodiment of the present invention.

FIG. 12 is a view taken in the direction of the arrows CC in FIG. 11;

FIG. 13 is a block diagram of a conventional example.

14A and 14B show an example of a target, in which FIG. 14A is a perspective view and FIG. 14B is an operation explanatory view.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Rotation irradiation apparatus main body 2 Target 5 Light emitting part 6 Rotating part 8 Control part 9 Light emitting element driving part 10 Scan motor driving part 23 Reflected light detecting part 32 Light receiving part 50 Light receiving element 51 Mask 60 Light emitting 1/4 lambda birefringent member 62 Polarizing beam splitter 63 Light receiving element 65 Mask

Claims (7)

[Claims] 1. A laser emitting unit that emits a laser beam, a rotating unit that irradiates a laser beam from the laser emitting unit to form a laser plane, and a tilt setting unit that tilts the rotating unit.
A target that reflects the laser beam from the rotating unit,
A laser irradiation device, comprising: a light receiving unit that receives a reflected laser beam in a predetermined direction parallel to the laser plane. 2. The laser irradiation apparatus according to claim 1, wherein a mask for limiting a light receiving range is provided on a light receiving optical path of the reflected laser beam. 3. The laser emitting section emits a polarized laser,
The target has a polarization-preserving reflection unit that preserves and reflects the polarization direction and a polarization conversion reflection unit that converts and reflects the polarization direction, and the light-receiving unit receives the reflected laser beam whose polarization direction is preserved. 2. The laser irradiation apparatus according to claim 1, further comprising a first light receiving means and a second light receiving means for receiving the reflected laser beam whose polarization direction has been changed. 4. The laser irradiation apparatus according to claim 1, further comprising at least a rotation section for rotating the inclination setting section and the light receiving section. 5. The laser irradiation apparatus according to claim 4, further comprising control means for controlling rotation of a rotating unit based on light reception of said light receiving unit such that an inclination direction of said inclination setting unit coincides with an inclination direction of said target. . 6. The laser irradiation apparatus according to claim 1, further comprising display means for displaying a match when the direction set by the tilt setting unit matches the direction of the target based on the light received by the light receiving unit. 7. The laser irradiation apparatus according to claim 1, further comprising control means for controlling an inclination setting unit based on light reception of the light receiving unit so that a laser beam is directed to the center of the target.